Crank-case vent



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C. C. FARMIEW CRANK CASE VENT Filed June 5, 1926 v INVENTOIR CLYDE C.IFARMER ATTDRN EV t lt ti l i;

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enema-case vane.

Application filed Inns 5,

This invention relates to fluid coniprcssets and more particularly to anatmospheric vent device for the crank case of the compressor.

Tn compressors of the reci inoeating piston type, the fluid in the crankcase is alteriiatecoinpressed and rarefied as the compressor pistonsreciprocate. It has heretofore been proposed to provide the cranlfr caseof a compressor of the reciprocating piston type with an atmosphericvent, so as to permit flow t fluid to and from the crank case.

When air from the atmosphere is drawn into the crank case on thecompressor stroke of the compressor pistons, dirt or particles offoreign material are liable to enter with the air, with the result thatthe particles become mixed with the lubricating oil and 20 tend to causeundue Wear of the bearings.

The principal object of my invention is to provide a c 'ank case ventdevice having means for preventing dirt or particles of foreign matterfrom entering the crank case of the compressor.

in the accompanying drawing; Fig. 1 is a side elevation of a fluidcompressor show ing my improved crank case vent device applied thereto;and Fig. 2 a section on the line 2-2 of Fig. 1.

The fluid compressor may comprise the usual casing 1 having cylinders 2,each containing a compressor piston 3, connected by connecting rod l tocrank shaft 5, which is contained in crank case chamber 6.

According to my invention, the crank case vent device is formed as apart of thebono pressor casing and consists oi Walls so dis posed as toprovide pockets 7 and 8 comniunicating with each other through anopening 9. l

The pocket 7 is open to the crank case chamber 6 through an opening 10,the enclosing wall 11 of which extends upwardly into a pocket 12 itormcdin the usual cover plate 13. The pocket 12 is sufliciently large toprovide a passageway from the opening to the crank case chamber.

Tn the pocket 8 is an inclined baffle plate ll adjacent to the opening 9and of less width than the Width of the pocket so as to provid anopening 15 for the passage oi fluid. Below 1.55%, a

iee'e. semi no. risers.

portion 16 is provided on the side wall or the pocket. having oppositelyinclined tacos 17 and 18. On the opposite side wall of the pocket is aprojecting portion 19 having oppositely inclined faces 20 and 21 and disposed below the projecting portion 16.

tilj'niced from the projecting portion 19 is a Web having faces and 24;disposed siiil'istanti'ally parallel with the faces 20 and 21. andii'aces 25 and 26, with face 25 parallcl with. face 18 and face 26 withan inclined face 2'? at a projecting portion 28 ct the eoirrespoi'idingside Wall of the pocket.

The tortuous channels formed by the web 22 and the side wall projectingportions open downwardly to the atmosphere. The pocket 8 is covered orenclosed by a cover plate 29, shown applied in Fig. 2, the cover platebeing removed in Fig. 1 to more clearly show the construction.

Tn operation, When fluid is exhaled from the crank case chamber, thefluid. is more or less laden with oil vapor and flows from said chamber,through the opening 10 to pocket 7 and thence through opening 9 andimpinges on face 30 of the plate 14. The direction oi flow thus changed,and fluid. continues its flow through opening 15, thence the. flowimpinges on face 17, chang ing the direction oil flow. Fluid then flowsthrough the channels formed at opposite sides of the web 22 and impingeson faces 20 and 25 and finally upon faces 24iand 27, after which thefluid escapes to the atmosphere.

In this flow ct fluid, the oil vapor carried by the air tends to bedeposited as oil globules 011 the several faces against which thecurrent of air impinges and this deposited oil film is made use of toprevent dirt particles from entering the crank case, as will now bedescribed.

When air is inhaled, the air flows in through the exhaust openings ofthe crank case vent device and. first impinges on the faces 21 and 26.Some particles of matter, heavier than air, tend to be deflected backtoward the exhaust openings and as the flow of air continues, thecurrent impinges on the faces 18 and 23, similarly deflecting some ofthe dirt particles. The flow of air then impin es on the face 31 and.iii flows upvvai 1y through the opening then through the opening 9 tothe pocket 7, whence the air flows through the opening 10 to the crankcase chamber 6.

The film of oil which tends to collect on the faces 17, 20, 25, 2 1, and27 tends to hold particles of foreign matter and prevent their entranceinto the crank case chamber and in time all. surfaces exposed to thecurrent of air within the vent device tend to become coated with a filmof oil which tends to collect dirt particles and prevent their en'-trance into the crank case chamber. If the oil film collects to asuiiicient extent, the excess oil will flow by gravity out through theexhaust openings of the vent device.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is

' '1. The combination with a reciprocating piston machine having a crankcase Cl121l11- ber,'of a crank case air vent device having portionsprovided with faces against which the air current laden with oil vaporexhaled from the crank case chamber impinges and on which oil tends todeposit, and faces against which the air current carrying dirt particlesimpinges when air is inhaled, the particles tending to be deflected backin part and in part to be held against movement to the crank casechamber by the dcposited oil, the faces on which oil tends to collectbeing disposed so that the mllevted oil tends to drain out to theati'nosphero by gravity flow.

2. The combination with a reciprocating piston machine having a. crankcase chamber, of a crank case air vent device having tortuous passagesthe walls of which act as bafl'lc plates to impede the movement of dirtparticles in the current of air flowing to the crank case chamber and assurfaces to collect oil in the current of air flowing out of the crankcase chamber oil so collecting serving as a medium to hold dirtparticles in suspension all oil collecting surfaces being i so inclinedthat oil collecting thereon will tend to flow by gravity to theatmosphere.

In testimony whereof I have hereunto set my hand.

CLYDE C. FA RMER.

